An allograft includes bone, tendon, skin, or other types of tissue transplanted from one person to another. Allografts are used in a variety of medical treatments, such as knee replacements, bone grafts, spinal fusions, eye surgery, and skin grafts for the severely burned. Allografts come from voluntarily donated human tissue obtained from donor-derived, living-related, or living-unrelated donors and can help patients regain mobility, restore function, enjoy a better quality of life, and even save lives.
When a ligament or tendon becomes detached from the bone, surgery is usually required to re-secure the ligament or tendon. Often, a substitute allograft ligament or tendon (hereinafter an “allograft construct” or “allograft tendon construct”) is attached to the bone to facilitate regrowth and permanent attachment. The reattachment procedure involves drilling a bone tunnel between two bones such as, for example, the tibia and the femur, and securing the allograft construct within the tunnel. To demonstrate this technique, Prior Art FIG. 1 shows an exemplary prior art allograft construct 50 secured within femoral and tibial tunnels 52, 54, each formed in femur and tibia 56, 58, respectively.
An allograft construct must be properly tensioned within the bone tunnel to achieve optimal results. That is, the tension or the “fit” of the allograft construct within the bone tunnel prior to being anchored to the bone must be sufficient to achieve stability, but not so excessive that it captures the joint. One variable in achieving optimal tension of the allograft construct within the bone tunnel involves preparing an allograft construct having the proper cross-sectional diameter. Preparing a construct with the requisite cross-sectional diameter typically involves folding a single tendon strand in half, which results two abutting tendon lengths having in a common middle region bounded by a folded end and a free end. The free end may then be whip stitched together. Alternatively, two separate tendon strands may be associated with one another, or “doubled up,” before one or both free ends are whip stitched together.
Prior Art FIG. 2 illustrates a partial perspective view of an unstitched middle region 59 and a free end 60 of prior art allograft construct 50, in which free end 60 has been whip stitched using a flexible strand to form a stitched pattern 62. Notably, the whip stitched pattern 62 of prior art allograft construct 50 originates inward toward unstitched middle region 59, from where a number of sutures 641-5 progress or advance outward toward free end 60 along arrow A. As a result, final suture 645 is located adjacent to free end 60, and pulling forces applied to the flexible strand along arrow B are transferred to final suture 645 at free end 60.
Prior art stitch pattern 62 is often applied to a folded allograft tendon, and discussed above. Alternatively, it is applied to two independent tendon strands that are stitched together at one or both of their ends using a similar whip stitching technique.
Traditionally, surgeons have been responsible for tendon graft preparation, individually preparing appropriately cross-sectioned, whip stitched grafts for each patient and/or circumstance. Recently, pre-sutured allograft constructs have become available from third-part providers, such as, for example, allograft processing centers, thereby allowing surgeons to order high quality, consistent, strong, and sterile tendon allografts, either individually or as part of a larger “kit” carrying a variety of sizes.